We're trying to override the auto-authenticate behavior when kicking off a web server flow in the REST API. Basically, we need to let a user authenticate and capture OAuth tokens to several Salesforce orgs in one session.

The problem is, once they authenticate to one org, the next time we redirect them to authenticate to another, they are re-authenticated automatically to the original org. We need to bring them to the login page each time in order to allow them to authenticate to multiple orgs.

In reading the docs, there doesn't seem to be a url param that will do it. I was hopeful that the immediate flag would accomplish this but it doesn't.